A plurality of fusible elements that are connected in parallel into an electric circuit is a much more effective arc extinguisher than a single fusible element having the same current-carrying capacity. This is particularly true where the currents under interruption are of a relatively small magnitude, or of medium magnitude, say in the order of ten times the rated current of the fuse.
A plurality of separate fusible elements is likely to form an initial clean break at least at one, or at several different points of the fusible elements. Assuming that but one break has initially formed in a plurality of fusible elements connected in parallel into an electric circuit, the remaining fusible elements, i.e. those in which no break has been formed as yet, must carry the entire fault current. This, in turn, greatly accelerates the formation of breaks and the velocity of burnback in the fusible elements which initially remained intact.
It is one object of the invention to provide a fusible element structure for electric fuses which utilises the above phenomenon and which greatly increase the probability of formation of breaks. Other objects of the invention will become more apparent as this specification proceeds.
The closest prior art known to me is U.S. Pat. No. 4,048,609; Sept. 13, 1977 to E. J. Knapp, Jr. for LATTICE STRUCTURE FOR ELECTRIC FUSES COMPRISING FUSIBLE ELEMENTS AND INSULATING SUPPORTS THEREFOR and Patent Application Ser. No. 849,171; Nov. 7, 1977 of Frederick J. Kozacka for COMBINATION OF FUSIBLE ELEMENTS FOR ELECTRIC FUSES.